Color Galaxy is a minimalist, IO-battle-arena game that features racing and painting themes. The player's primary goal is to drive a car around inside of a fenced arena while pouring paint onto the ground to mark a territory without getting killed by other characters. The game offers a "fill-in" aspect similar to classic paint-bucket tools found in graphics and photo editors. The player needs to draw a line until they've made a closed loop with the paint to create a fill spot. They must also try to kill their competition by driving over the unprotected lines of other drivers.
The player earns coins when they fill in their territory and take out other drivers, cars and territories. They can use this in-game money to upgrade their car and fill-color options. They can also buy stickers and event items. They even receive opportunities to win exclusive offers and other rewards. For example, they can play in-game side quests to collect specific vehicles or fill-in colors, such as a fire engine, an ambulance or a police car, respective fill colors or crime stickers.
During gameplay, Color Galaxy also helps the player keep up with their stats on a Scores menu, including their total number of wins, max kills, max territory, max piece and best time.